Web-tensioning mechanism for use on printing machines



9 'r. R. BENNETT ETAL WEB-TENSIONING MECHANISM FOR USE ON PRINTING MACHINES Filed March 8, '1950 3Sheets-Sneet l ATT Rim-Y.

T. R. BENNETT ETAL Nov. 11, 1952 WEB-TENSIONING MECHANISM FOR USE ON PRINTING MACHINES 5 Sheets-Sheet 2 Filed March 8, 1950 INVEN TORS.

'oRNEY.

1952 TR. BENNETT ETIAL ,6

WEB-TENSIONING MECHANISM FOR USE ON PRINTING MACHINES Filed March 8, 1950 3 Sheets-Sneet 5 l g F: T E L E 23 Tiff /NYEN7'0RS BY v ATTORNEY.

Patented Nov. 11, 1952 v r st 0mm WEB-TENSIfiN'I-Nfiw FORIUSE ON PRINTING MAGHINELSI Thomas Richard Bennett, K-mgsbury, London,- and Claude Ed-Ward Frederick Willis, Niorbnrm, Londom: England; assignors: to R. Hoe &: 00., Inc. New York; N; Y., a corporation of. New York Application March 8, 1950-, Serial No. 148,304 In Great Britain March: 14, 1949 3, Glaimse (Cl. 242-75) invention; relates to mechanism for use Figure; 2 but with, a cover removed; to; show im.controlling tensiorriin a, web: passing.-

mechanism within the box and. Figure! as).

at weliiusing: machine or at box; making machine sectional side elevationrapproximately on the line invention. is; concerned; with apparatus) of. IST-4V Figure 3,, Figures; 3 andv 44 being. orija. the t which comprises; a; component which: larger scale than Figure 2. Fig, 5 is a, localsec moves in: response to: change: in the tension tional; plan. and Figure 6 is a, localv side. elevar the, web andwhich causes: by: its. movement the:- tion of, a modification, Figure 7c is a pictorial.

operation, of; a tension regulating device so:- as wiring. diagram oi that part of the control ci'rto: maintain; the tension; ata sensibly constant; cui't. of a webrconsumi'ng machine with which value-:1 this, invention is. concerned;

Now according to one feature of the: present Referring further to Figure 1;. which indicates; invention; there: is: provided, webr-tensioniing generally the kind of mechanism with which the apparatus-ct the: kind referredtoga tensiomcon-= invention is concernedQa web roll i is supported troL niechanism. which, comprises; as support, a; to rotate in a support and the web: 3fi'om this switch-openatingtcomponent monahlezonthe-sun-- roll. is taken over. rollers, ie-T whence it passes punt: the tension responsive component, the: to the machine operati'ngonthe web; The: 101i".- switch; operating; component; being: operatively er 6. is. a floating roller and. is" carried' at the assoeiated. with; a. switchto. efiect electrical outer end of, an arm structure 8 carried by a of. the tension. reguiating; denies; and; :spindie: B. Thus this rolleri's' free to rise-- and" means: to: adjust the setti'ngxn".v the support and fall in response to change in the tension. in

hence; thenomnial'; setting oi; web: tension; the web" 3. Tension is regulated by a; series of belts said: means; comprising: an electric motor the: off which one is indicated. at Hi, the belts-passing? controlicircuitofwhiclrcan beextended; tnlareover rollers H, [2; 13; The rollers IZ" are so mote control; station. Preferably the support drivenby a: drive taken from the weh-consum mounted to pivot on. afixerizpiyoir and theswi'tcn ing' machine that" the Speed of the belts [03' is component is? pivotally mounted-en EL ii'gh ly below" the speed at which the machine pivots cm the support: at; a point; remote; from draws the web forwardly; the belts time im,-

its-1 pivotal; mounting-a.v The; switchroperating; posing'a tension in the-web. The deg-reeof ten-f 7 component conveniently" formed, with a cam; sionis regulated by mounting; l r H n" to; engage: arswitoh: actuating device: the rear 30- a frame It which can" swing abou thecent're-of ion the: pivotal: mounting of? the support so; the roller i2 and-s0 vary the pressure of the 1311813,? connotation is substantially; unaifected. by." belts- H! against r nning roll I; nd? he thejirocicingmouementioffthesupport. degree of their wrap about itsperiphery;

According; to a, further feature: of the inve rocking of the frame l-fi is eifeotedbyarever'sible tiom. web; ,tensioning: apparatus of. the: '35 motor l 'fi reierned to there is: provided a; remote: control: The mechanism so far referred to: s Well system comprising; aneleotrmmotor t operate; known and} it is therefore believedto" be un-r the: tension; regulating; device; a switch to CD11? c y o ve er etafis- The' invert-- trolithe energisationiofi the motorami"v controlledi tion is concerned with the mechanism by which:

by; the tension; responsive component and: a; sec! 41) the motor 16? is regulated to effect control" in and; electric: motor to: adiust; thenom'inala' postthetcnsion of the web-31 ti-OflzrOf, the; onerationofi thewswitchs the: control: Reference will now be mad'e: to Figures 2;:4

circuit of the: second motor extendings'to the; re..-= and 7? In Figures and t e e is indicated a;

V motecontrolzstationr The apparatuswoulch also: control box H having acover I-8 which-is re:--

include an electrical potentiometer'or similar d6?" 4' moved in Figure 3. this box there is pro? vioe-=whichwilltransmiti20 thev remote; control vided a support 01-" bracket; I9 which. ismounted station signal; enabling, the actual; setting; to for rocking movement about a. fixed-pivot.

hei'ndicatedat that-station. V This bracket is pivotally connected? at Zl at a The invention is;- illustrated. in, the aooom'r- P0111111 placed from the fi'xed pivot 21). to a;

panying; drawingszirr which;.Figure,=1'is:a side;e1e-- so screwed rod 22' engagin afnut 23 fixed in the;

vation v showing: in elevation a;v websuppiy. ar I wall of the box; 11'. The nutis. coupled: as rangement incorporating the. parts: according to" gearing oras shown by: afiexi bl'ehand 2Wpassthis invention, Figure 2 isa side elevation of the ing over a pulley 24 to a reversibie electric ma reomponent or controt box according to this motor- (shown at 25 in; Figure 1:) sothat' when invention; Figure 3: is: a view corresponding to:

the: circuit: of' this motor is ciosed the: nut- 3 rotated and in consequence the bracket I9 is caused to rock on its pivot 29 in one direction or the other.

The bracket I9 has pivotally mounted on it at 26 again at a point remote from its fixed pivot 20 a lever 21 to which is pivotally connected at 28 one end of a strut 29 the other end of which is pivotally connected at 30 to an arm 3| on the spindle 9 of the arms 8 carrying the floating roller 6. This lever 21 has a cam surface 32 disposed to engage a roller 33 at the end of a switch-operating rod 34 to operate a doubleacting switch S shown in Figure 3, and comprising wiper contacts 35, 36 to engage contacts 31, 38 connected respectively in the forward and reverse lines of the motor It. The cam 32 and the roller 33 on the switch operating rod 34 are disposed to engage in the region of the fixed pivot 29 of the bracket I9 so that movement of the bracket about that pivot 20 has little or no eifect on the co-operation between the cam 32 and the roller 33.

The nominal setting of the bracket I9 and hence the nominal setting for the tension in the web is determined by energisation of the motor 25 under the control of a remote tension-setting controller hereinafter referred to. Since the motor 25 operates through the screw 22 the bracket I9 becomes in any position to which it is moved under the remote control, a fixture on which the lever 21 can rock about its pivot 25 in response to change in the web tension (either by an increase or a decrease of tension) with respect to that corresponding to the nominal value corresponding to the setting of the bracket I9. When such change occurs, the lever 21 is caused to rock in one or other direction on the bracket I9 and its cam surface 32 operates to control the position of the switch-operating rod 34 and so to close the increase or the decrease side of the switch S. When this occurs the motor I6 is energised to rock the frame I9 which operates to counteract the change in tension and to restore it to the value corresponding to that of the setting of the bracket IS. The depletion of the running roll tends to reduce the pressure of the belts I and to lower the tension on the web. This causes a lowering of the roller 6, which then acts through the controls to lower the belts I0 and restore the normal web tension. In order that the nominal value of the web-tension can be set by local hand operation at the web supply station, the pulley 24 which is normally driven by the motor 25, is provided with an operating handle 53 by which the rod 22 can be rotated to produce as has been described, the tension regulation which is normally elfected by energisation of the motor 25. The rollers 5, 9 and 1 are positioned in such relationship that a greater tension on the web is produced if the roller 6 is held by the web at a relatively high elevation than if it is held at a lower elevation. By adjusting the mechanism for increasing and decreasing tension to operate in a low portion of the are through which the roller 6 can swing, a relatively low web tension will be maintained, or by adjusting it to operate in a high portion a higher web tension will result. Hence by means of the handle 53, the pulley 24 may be rotated to so adjust the controls, that the floating roller will be carried at the level that will produce the desired normal web tension.

For the purpose of afiording a local'visual in dication of the nominal tension setting, there is provided a pointer 42 to move over a fixed scale 43. The pointer 42 is secured to a spindle 44 having an arm 45 coupled by a link 46 to the lever 21, the link being free to pivot on the lever 21 about the point at which the lever is pivoted to the strut 29. When the bracket I9 is adjusted by the motor or by the hand-wheel 24' the movement of the bracket I9 will operate through the link 46 to cause the pointer 42 to indicate the change in nominal web tension.

-As however the linkllfi can pivot about the pivot on which the lever 21 rocks in response to fluctuation in web tension with respect to the nominalsetting, the fluctuations will not cause the pointer 42 to move with those fluctuations.

As has been stated the tension regulating apparatus is adapted for remote control from a control station. A convenient arrangement is shown in Figure 7 in which the control line of the motor I6 from the switch S (which is within the control box .I1), is indicated at 39 and in which the control line II of the motor 25 is taken to increase or decrease switches on a control panel 51 located at any convenient position in the machine room. For example it can be located at the delivery of a printing machine. (or any equivalent switch mechanism) the nomlnal tension setting of the web-tension can be regulated by control exercised from this remote panel.

The nominal web-tension setting is indicated locally by the pointer 42. To enable a related indication of nominal web tension to be given at the tension control station 51 the arm is extended by a second arm 41 which is linked by a link 48 tothe arm 49 of an electrical potentiom-. This potentiometer is included by a .those lines can be switched to the various remote control panels 51, 83, 64, the switch enabling the motor 25 and the potentiometer 59 to be connected to any one of those control panels.

So as to minimize any tendency for the floating roller 6 to hunt or oscillate and so to cause corresponding hunting in the value of applied web tension, the increase and decrease sides 31, 38 of the control switch S are so spaced that the movable switch component 35 has an idle movement in which no control is'effected. This enables any small fluctuation in web-tension aft-' or an increase or a decrease control has been exercised to occur without regulation and this enables conditions to settle down after such a control has been applied.

Reference will now be made to Figures 5 and 6. These figures illustrate an arrangement which can be employed to prevent the screw-thread of the rod 22 from jamming in the nut 23 at each limit of the travel of the rod especially when it is operated by hand. The hand-Wheel 24' has a limiting abutment 54 on it and in the side wall of the box I1 is provided a stop pin 55 which is normally held by a spring 56 in a retracted position clear of the abutment 54. On the arm 4! By operation of these push buttons 40.

is secured a trip plate 510 which swings with the arm 41, so either one end or the other of the plate 510 will press down the stop pin 55 when the arm 41 approaches a position corresponding to either limit of travel of the screwed rod 22. When this engagement occurs, the stop pin 55 is forced outwardly against the action of its spring 56 and so comes into position to oppose continued movement of the abutment 54 and hence of the nut 23, beyond the limiting position.

In the arrangement as shown in Figure 1 the invention is applied to the familiar web-renew ing mechanism in which the support 2 for the roll I is in the form of a 3 arm spider 5-80 which has two other roll positions 59, 60 of which the roll positions 59 can be regarded as that of an expiring roll and the roll position 60 as that of a freshly loaded roll, the spider 580 being turned (as by motor 5|) to carry its roll positions successively into position to enable a-web passing from the running roll to be joined to the web of a replacement roll and the running web is severed by mechanism indicated at 62. In such equipment the pressure of the belts I0 is reduced by the depletion of the running roll and consequently the belts must be lowered at frequent intervals in order to maintain a constant web tension.

This apparatus forms no part of the present invention and is in any case well known so that further description in this application is believed to be unnecessary.

We claim:

1. Web tension control mechanism comprising in combination a tension-responsive component supported for movement in response to change in tension, a tension regulating device to effect change in web-tension, a tension control mecha in combination a tension responsive component supported for movement in response to change in tension, a tension regulating device to effect change in web-tension and a tension control mechanism comprising a support mounted to swing on a fixed pivot, a switch operating component which is mounted to swing on the support on a pivot remote from the pivot of the support, an electric switch to control the operation of the tension regulating device, the switch operating component effecting actuation of the switch by its pivotal movement on the support, means coupling the switch operating component to the responsive component for movement therewith, a screw and nut gear to adjust the support on its pivot, an electric motor to rotate the rotatable member of the gear, a manually operable component to rotate the rotatable member of the gear and means controlled by the movement of the support to hold the rotatable member of the gear against rotation beyond extreme limiting positions.

3. Web tension control mechanism comprising in combination a tension-responsive component supported for movement in response to change 7 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,170,840 Morse Feb. 8, 1916 1,869,614 Phythian Aug. 2, 1932 2,361,856 McMullen et al. Oct. 31, 1944 

